Denali Driver

Hi, That sucks to hear the Duramax is experiencing the same issue a the gas engines. I've run into other Duramax owners who are trouble free. Does the diesel engine disable cylinders (Dynamic Fuel Management) while on the highway like the gas engines? I had a similiar experience (alarm) on my 5.3 but not until @ 46000 kms. My dealer thinks maybe my piston rings are not in the right place on a couple cylinders but i doubt it. I just might go ahead and get this DFM disabled because a few of my spark plugs get badly fouled and the others are normal. Good luck, I'll follow this thread.

Hi, It appears all these gas engines from the 2019 and newer half tons are consuming oil. I hear a lot of the same and worse consumption from other GM and Chevy owners in my area. My oil consumption issue was first noticed @ 46000 kms in (March 2022) roughly 1000 kms from previous oil service. The "add oil indicator" came on (PANIC Situation). When i pulled the dipstick there was nothing visible! Rather than add to fill i drained the oil and filter to see what was left in the sump. This 5.3 has a 9 quarts capacity and i was down roughly 4 quarts. I have since been to my dealer twice and both times sent on a 3000 km oil consumption test checked every 500 kms and recorded after 15 min shutdown. Perhaps maybe the first time back in Feb / March i idled my vehicle to often (as we had -40 Celsius weather consistently) so that was a possible cause. However since that time I have put on 20000 kms and on average I burn 1 quart / 1000 kms. (on occasion I will get puff of blue out the tail pipe at start up and can smell burning oil) but not always. It has a struggle with my dealer! they "GM Canada and Shop foreman" have basically called me a liar saying there is no way it will burn so much. Now after all these added kms this dealer wants the truck back to tear apart the engine to investigate why this is happening. I live up northern Canada and It is a 6400 kms round trip to my dealer which explains the roughly 21000 kms added in 5 months (now at 67000 kms). Those 2 trips to my dealer cost me @ 7 grand for a carrier, fuel, hotels and 2 flights etc. That has cost a lot of money, headache, downtime, wasted travel and unnecessary added kms taken from my basic 60k / 3 yr factory warranty which General Motors Canada will not be paying back! I say these newer engines have an issue!

Hello, Could your concern be the dynamic fuel management deactivating cylinders? I have a 2019 5.3ltr Denali 1500 and i noticed more so lately with a sort of like hesitation or vibration at highway speeds. Can also see the tachometer fluttering @ 1500 rpm. Also recently, yesterday as a matter of fact replaced all 8 spark plugs because i had an ignition alarm code come upon cylinder # 8. The spark plug was fouled badly. Tested my truck today and it felt a little better. I also have a burning oil concern on my truck average 1 quart / 1000 kms.

Hi Folks, Glad to hear this issue with "service 4WD" is not isolated to my 2019 Sierra Denali 1500. I First experienced it shortly after 3000Kms in wet snowy muddy highway conditions while in 4WD auto mode. The auto mode went from white to amber color and when i stopped the vehicle the E-Brake automatically applied. After driving on into better highway conditions the auto indicator light color, service 4WD light and E Brake all corrected itself. This has happen multple times since and i now have 12000 kms on the vehicle. I still haven't informed my dealer about this issue. The other issue is with "rabbits" apparently they love to chew on my block heater cord. I've had to shorten that cord a couple of times and wrap it with duct tape. Good luck everyone.